PURPOSE:We conducted a prospective study to evaluate the incidence of upper extremity lymphedema following moderately hypofractionated regional nodal irradiation (MH-RNI) for breast cancer. We incorporated both standardized and expanded arm measurements to determine whether more granular assessment improves lymphedema detection. METHODS AND MATERIALS:This prospective, single-institution trial enrolled women with non-metastatic, lymph node-positive or high-risk node-negative invasive breast cancer following lumpectomy or mastectomy with an indication for RNI. Patients were stratified based on extent of axillary surgery: SLNB (≤5 nodes removed) versus ALND (>5 nodes removed). All patients received 42.56 Gy in 16 fractions to the breast/chest wall and regional lymphatics. The primary endpoint was cumulative incidence of clinically significant upper extremity lymphedema at 3 years. Lymphedema was assessed prospectively, using standard, 2-point circumferential measurements and additional exploratory circumferential measurements obtained at 10-cm intervals along the upper extremity. Competing-risk methods were used for lymphedema analysis, and Kaplan-Meier methods were used for time-to-event outcomes. RESULTS:Fifty-two patients were included; forty-one (78.8%) underwent SLNB, and eleven (21.2%) underwent ALND with a median (IQR) of 3 (2-4) and 10 (8.5-11.5) nodes removed, respectively. The cumulative incidence of lymphedema for all patients was 6.4% at 36 months; 5.7% following SLNB versus 9.1% following ALND (Gray's test p=0.62) with no additional events through 60 months. Additional 10-cm interval measurements did not detect lymphedema earlier than standard measurements or identify any additional cases. Acute and late side effects were predominantly grade 1-2, with no grade ≥3 late adverse events. No locoregional recurrences occurred. DMFS and PFS were 93.4% at 36 months and 87.9% at 60 months. OS was 97.2% at 36 and 60 months. CONCLUSIONS:MH-RNI was associated with a low incidence of upper extremity lymphedema, minor toxicity, and excellent intermediate-term disease control. Extended circumferential measurements did not improve detection of clinically significant lymphedema, supporting the adequacy of standard, two-point measurement techniques for clinical practice and future trials.
PURPOSE:Radiation-induced temporal lobe injury (RTLI) remains a major late toxicity in T4 nasopharyngeal carcinoma (NPC) because primary target volumes frequently overlap the temporal lobe planning risk volume (PRV), limiting near-maximum dose constraints. This study evaluated the long-term safety and efficacy of an overlap-adapted subvolume prescription strategy. MATERIALS AND METHODS:This non-randomized, single-institution, prospective observational cohort study with a contemporaneous comparator (ClinicalTrials.gov identifier: XXXX) enrolled patients with T4N0-3M0 NPC treated between 2018 and 2022 who had planning target volume (PTV)-temporal lobe PRV overlap ≥ 0.1 cm3. The modified delineation and planning (MD) approach subdivided the primary tumor PTV (PTVnx) into a non-overlap subvolume (PTVsv1, prescribed 70 Gy) and an overlapping subvolume (PTVsv2, prescribed 66 Gy) using simultaneous integrated boost. The standard delineation and planning (SD) approach prescribed a uniform 70 Gy to the entire PTVnx. RESULTS:Among 361 patients (MD, n = 104; SD, n = 257), the 5-year cumulative incidence of RTLI was significantly lower in the MD group (23.2% versus 36.2%; P = 0.019). Multivariable analysis revealed that MD was independently associated with reduced RTLI risk (hazard ratio = 0.56; 95% confidence interval: 0.34-0.94; P = 0.029). No significant differences were found in 5-year local relapse-free survival (92.3% versus 89.6%; P = 0.577) or overall survival (84.7% versus 84.4%; P = 0.896). No marginal recurrences were confined to PTVsv2. After lobe-level propensity-score matching (205 lobes per group), MD achieved significantly lower temporal-lobe Dmax and D1cc (both P < 0.001) without differences in V40-V60 and a borderline reduction in V65 (P = 0.053). CONCLUSIONS:An overlap-adapted subvolume prescription strategy (66 Gy to PTVsv2) significantly reduced the incidence of radiographic RTLI while preserving long-term tumor control in anatomically constrained T4 NPC. The reduction in symptomatic RTLI was numerical but did not reach statistical significance and warrants further validation.
Background As survival after early-stage breast cancer improves, competing health risks such as ischemic heart disease (IHD) are increasingly relevant. Coronary artery calcification (CAC) is a validated marker of coronary atherosclerosis and is frequently visible on non-contrast CT. Radiotherapy simulation CT may offer an opportunity to detect subclinical coronary atherosclerosis in asymptomatic patients. Methods A retrospective cohort study was conducted including patients aged ≥65 years undergoing adjuvant radiotherapy for early-stage breast cancer. CAC was visually assessed on simulation CT using a three-level score: 0 (none), 1 (mild focal calcification), and 2 (extensive calcification). The primary endpoint was incident IHD during follow-up. Associations were evaluated using exact logistic regression. A survey of radiation oncologists assessed current reporting practices. Results A total of 207 patients were included, with a mean follow-up of 6.6 years. Six patients (2.9%) developed IHD. CAC was absent in 89 patients (43%), mild in 60 (29%), and extensive in 58 (28%). All ischemic events occurred exclusively in patients with extensive calcification (6/58, 10.3%) and none with lower scores (0/149 patients, 0%). Extensive CAC was associated with increased risk of IHD (odds ratio (OR) 22.8, p=0.0008). Among patients without pre-existing IHD (n=189), the association remained robust (OR 17.45, p=0.006; age-adjusted OR 18.47, p=0.008). Notably, although patients with known IHD had a greater calcification burden overall, 4 of 6 events occurred in patients without known cardiac history, all with extensive CAC. Across 32 surveyed radiation oncologists, only 12.5% reported routinely documenting CAC, while 78.1% indicated willingness to modify practice if clinical relevance were established. Conclusions Extensive CAC on breast radiotherapy simulation CT is strongly associated with subsequent IHD but is infrequently reported in clinical practice. Incorporating structured assessment into routine reporting may improve cardiovascular risk stratification and preventive care.
Carbon-ion radiotherapy holds promise for central lung cancer owing to its noninvasiveness and precision. We report a case of lung squamous cell carcinoma treated with neoadjuvant chemoimmunotherapy followed by carbon-ion radiotherapy. The course was complicated by severe checkpoint inhibitor pneumonitis with concurrent Pneumocystis jirovecii pneumonia and subsequent recurrence, highlighting the challenge of managing multimodality toxicities during aggressive local control.
PURPOSE:Radiation oncology (RO) resident participation in quality improvement (QI) is mandated in the United States by the Accreditation Council for Graduate Medical Education (ACGME); however, the degree of involvement and methods of implementation are not specified. This study evaluates a resident-driven QI incentive program at a single institution over a 15-year period. MATERIALS AND METHODS:Residents in a RO program were encouraged to develop, implement, and evaluate an annual QI project. At the completion of the academic year, residents were eligible for a financial incentive if the pre-determined QI goal was met. The primary outcome in this study was program sustainability, defined as the number of years with resident participation divided by the total number of program years. Project success was defined as meeting the pre-determined annual QI goal. Scholarly impact was measured by the number of scholarly works (manuscripts, abstracts, or posters) that resulted from resident-led QI projects. Project sustainability was also assessed, defined as continued efforts in the three years following the QI project. All data was obtained from retrospective review of projects and related presentations. RESULTS:From 2010-2025, RO residents led 14 QI projects as part of a QI incentive program. Program sustainability was 93%. Project success was 93%. Over the 15-year period, 12/14 (86%) projects led to scholarly works. Project sustainability was 100%. CONCLUSIONS:This study shows that a resident-led QI program was sustainable, academically productive, and effective in meeting resident QI goals. Since this was a single institution study, future work is needed to determine feasibility for other programs.
PURPOSE:Despite decades of use, multiple prescription strategies continue to coexist in lung stereotactic body radiation therapy (SBRT). An accurate prescription should reflect the dose delivered throughout the breathing cycle with minimal bias and high precision. This study aimed to evaluate the accuracy of widely used lung SBRT dose prescription methods by assessing which method most accurately represents the true delivered dose to the gross tumor volume (GTV), considering absolute terms (trueness) and consistency across patients (precision). METHODS AND MATERIALS:Fifty lesions were analyzed using combinations of computed tomography (CT) types (single phase, average intensity projection, maximum intensity projection [MIP]), target volumes (GTV, internal target volume, planning target volume [PTV]), dose prescription metrics (D2%, D50%, mean, D95%, D98%) and dose calculation algorithms (collapsed cone, Monte Carlo, and type A pencil beam). Delivered doses were compared against a 4-dimensional CT-based reference to assess trueness and precision across different prescription methods, including respiratory movement. RESULTS:Combinations involving internal target volume or GTV with single-phase CT or average CT, and based on D50%, mean dose, or D2%, showed biases of less than 2% and precision better than 1.5% when compared to the delivered 4-dimensional GTV dose. This was also valid for D2% PTV prescriptions. PTV MIP-based prescriptions showed surprising accuracy with primarily a constant 5.3% bias correction and 1.5% precision. However, MIP-based D2% and D98% were no longer coherent. Historical type A dose calculations resulted in low accuracy for any prescription method due to algorithm limitations. However, even with current type B/C algorithms, prescriptions based on 98%/95% PTV coverage on any CT still exhibited low precision, approaching that observed with type A calculations. This results in substantial interpatient variability in GTV dose, due to a linear bias correlated with PTV density, reflecting multiple underlying physical factors. CONCLUSIONS:The results of this study can be used not only to improve consistency in lung SBRT prescriptions but also to provide correction factors and weightings to improve accuracy in meta-analyses and dose-response modeling.
PURPOSE:This guideline provides evidence-based recommendations on the use of radiation therapy (RT) for the treatment of pancreatic cancer in a variety of clinical settings including patients with resectable, borderline resectable, locally advanced, metastatic, and symptomatic disease. METHODS:The American Society for Radiation Oncology convened a multidisciplinary task force to address 4 key questions: (1) indications for and timing of RT for patients with nonmetastatic pancreatic cancer; (2) appropriate RT dose-fractionation regimens and target volumes for nonmetastatic disease; (3) preferred RT planning and delivery techniques for nonmetastatic disease; and (4) indications for RT in the locally recurrent, metastatic, reirradiation, and palliative settings. Recommendations are based on a systematic literature review and were created using a predefined consensus-based methodology with a system for grading evidence quality and recommendation strength. RESULTS:Multidisciplinary evaluation and decision-making are recommended for all patients. For patients with nonmetastatic pancreatic cancer, RT is conditionally recommended in the preoperative and postoperative settings for resectable disease. RT is recommended preoperatively for borderline resectable disease and definitively in the locally advanced setting. For preoperative RT, conventional fractionation or moderate hypofractionation is recommended. For postoperative RT, conventional fractionation is recommended. In the definitive setting, conventional fractionation is appropriate although emerging evidence supports dose escalation using either stereotactic body radiation therapy (SBRT) or moderate hypofractionation. Adaptive RT is recommended for dose-escalated SBRT. Elective coverage of at-risk anatomic regions is recommended for preoperative, postoperative, and definitive RT. In the locally recurrent setting, RT is recommended for patients without prior RT and conditionally recommended for those who have previously received RT. Palliative RT is recommended for patients with bleeding, pain, and obstruction. For patients with oligometastatic and oligoprogressive pancreatic cancer, RT is conditionally recommended to metastatic lesions and the primary tumor if not previously treated with definitive local therapy. Target volumes, simulation and planning techniques, and treatment recommendations are provided. CONCLUSIONS:These evidence-based recommendations provide guidance on the optimal use of RT for pancreatic cancer. Ongoing and future studies should further refine RT indications, sequencing with other therapies, and impact on patient outcomes.
PURPOSE:The purpose of this study is to explore whether spacer hydrogel morphology changes during the course of stereotactic body radiation therapy (SBRT) radiation to the prostate. METHODS AND MATERIALS:A total of 198 patients at our institution each received spacer gel before SBRT on magnetic-resonance-guided linear accelerator (MR-Linac) between October 2023 and March 2025. Each patient received at least 1 simulation magnetic resonance imaging and 5 on-treatment magnetic resonance imaging scans. Average time between simulation and first treatment and between simulation and final treatment was approximately 19.9 days and 31.1 days, respectively, with 2- to 3-day intervals between treatments. A U-Net deep learning model was implemented using nnUNetv2. This model was iteratively trained using inference images, resulting in a Dice similarity coefficient >0.98, and was then applied to detect changes in gel morphology over time. RESULTS:Longitudinal modeling of spacer gel radiomic shape features demonstrated a statistically significant change in flatness that remained significant over false discovery rate correction and all sensitivity analyses. This metric increased by 0.003 units per 10 days (95% CI, 0.001-0.005; false discovery rate q ≈ 0.02), implying a progressively rounder shape over the observation period. All other features showed minimal or inconsistent change. The hydrogel appeared larger on treatment imaging, with a mean percent change of 10.62% (95% CI, 8.68%-12.56%; P < .001). The corresponding absolute volume difference was 1.19 cm³ (95% CI, 1.00 cm³-1.39 cm³; P < .001). CONCLUSIONS:Because prostate SBRT planning assumes gel stability, interfractional changes could affect rectal dose estimates. In this cohort, the spacer hydrogel's overall geometry remained stable across the 5-fraction course, with no meaningful evidence of gel resorption. A small increase in the flatness metric was observed, but without a change in size or compactness. These findings indicate that the gel maintains its rectal-sparing configuration throughout SBRT.
Bullous pemphigoid (BP) is a rare autoimmune blistering disorder increasingly recognized as an immune-related adverse event associated with programmed cell death protein 1 inhibitors, with limited data describing its occurrence in the setting of concurrent radiation therapy (RT). We report a case of a 50-year-old woman with stage IIIB triple-negative breast cancer treated with neoadjuvant chemoimmunotherapy followed by mastectomy and adjuvant pembrolizumab who developed BP during postmastectomy RT with regional nodal irradiation. After 7 fractions, she developed bullous lesions initially outside the radiation field, with subsequent progression to involve both irradiated and nonirradiated skin as well as mucocutaneous surfaces. Biopsy demonstrated subepidermal vesicular dermatosis consistent with BP, later confirmed on repeat biopsy with direct immunofluorescence. RT and pembrolizumab were held, and she was treated with systemic corticosteroids and steroid-sparing therapy, although her course was prolonged and relapsing, ultimately requiring permanent discontinuation of immunotherapy. This presentation, including early onset during RT and distribution beyond the treatment field, supports a synergistic interaction between RT and programmed cell death protein 1 inhibition, potentially mediated by enhanced antigen presentation and loss of immune tolerance. Because combined-modality therapy becomes more common, clinicians should maintain a high index of suspicion for immune-mediated toxicity, particularly when findings are atypical for radiation dermatitis, to facilitate prompt diagnosis and multidisciplinary management.
